Snap-lock wrench



Dec. 5, 1950 B, BURNS 2,532,659 l SNAP-Loox WRENCH Filed June 1, 194e /N VENTO/e.

BRUCE BUR/vs BY H15 ATTORNEYS. Hman/s, K/:cfg Fos TER Hmm/s @y v 'auf c. l

Patented Dec. 5, 1950 UNITED STATES PATENT OFFICE` SNAP-LOCK WRENCH Bruce Burns, Yucca Valley, Calif.

Application June 1, 194s, serial No. 30,336

(ci. :x1-s4) s claims. l

The invention relates to improvements in a wrench of the type commonly known as a toggle Wrench or vise-wrench wherein one of a pair of jaws is adjusted into contact with an object positioned between said jaw and the other jaw and the one jaw locked in a closed position to securely and firmly grip the object until the one jaw is released.

Such wrenches of this type as have been constructed in the past possess inherent structural characteristics which have rendered them dilcult to use in confined quarters. It is very easy with wrenches of this type to overadjust the movable jaw of the wrench so that when the jaw is once lockedagainst said object it becomes very difficult to release it therefrom and it frequently requires as much expenditure of energy to release the movable jaw of such a wrench from the object as was necessary to originally clamp it thereupon. The closing and clamping operation is performed by gripping a pair of handles and forcing them toward one another in much the same manner as the handles of a pair of ordinary pliers are manipulated. In such a situation the hand works in a position of maximum advantage and can apply great closing force with little conscious physical strain. The user of the wrench can thus close and lock an overadjusted tool inadvertently or without being very aware of the degree of overadjustment. In the opening or releasing operation, however, when it is necessary to force the handles apart, one hand works in an unnatural position and at a disadvantage. It will be observed frequently that a wrench may be closed and locked on the work with one hand and without apparent expenditure of undue force, but when a similar force is required for release, both hands must be used. A

Since prior art wrenches of this type have depended upon an outward movement of the handle associated with the movable jaw to release said jaw when wrenches thus constructed are, utilized in confined quarters, the great application of force vnecessitated to release the movable jaw from an object clamped thereby frequently results in the user of the wrench sustaining minor injuries because of sudden contactv with surrounding areas upon the sudden release of the jaw from the object.

' Since the release of the movable jaw in prior art wrenches necessitates the outward movement of one of the handles of the wrench in relationship to the other, the user of the wrench is often compelledtouse both hands when releasing the wrench from an object clampe thereby. Thus, since both hands of the user of the wrench are engaged in releasing the wrench from the object, it is necessary to permit the object to fall from between the jaws of the wrench when released. AA Wrench of the vise-wrench type embodying the improvements which constitute the subject matter of my present invention eliminates to aV great degree the above outlined difliculties encountered in prior art wrenches. A visewrench constructed in accordance with my invention may be opened with one hand and a far greater amount of leverage is available in opening the wrench than isavailable in closing it. Therefore, the difficulty encountered in prior art wrenches with overadjustments of the movable jaw is obviated.

VA vise-wrench constructed in accordance with my present invention may be opened with one hand because the release of the movable jaw is achieved by moving one handle of the wrench inwardly in relationship to the other handle, instead of outwardly as was previously the case. Naturally, such inward movement of the handles of the wrench in relationship to each other greatly facilitates the release of the Wrench from an object in conned quarters since it is no longer necessary to insert both hands into a conned space and attempt to move the handles of the wrench outwardly in relation to each other to effect the release of the wrench from an object. rvOf f course, since the wrench may be readily released with one hand, the user of the wrench may support the object clamped by the Wrench with his other hand and the release of the jaws of the wrench from the object need no longer occasion the dropping of the object to the workbench or ground.

Therefore, a primary object of my invention is the provision of a vise-wrench which may be readily released from an object clamped in said Wrench with one hand.

It is another object of my invention to provide a vise-wrench which may be opened by moving one handle of the wrench inwardly in relationship to the other handle.

Another object of my invention is the provision of a vise-wrench which may be more readily utilizedY in confined quarters than has been possible hitherto with prior art vise-wrenches.

A further object of my invention is the provision Vof a vise-wrench which is so constructed that the mechanical advantage utilized in releasing the wrench from an object clamped therein is much greater than the mechanical ad vantage provided in the initial clamping of the wrench upon the object.

A further object of my invention is the provision of improvements for wrenches of the vise-wrench type which can be manufactured and sold in the :form of a kit and which can be readily installed upon prior art wrenches already in use, thus eliminating the necessity of discarding prior art wrenches in'order to achieve the advantages of the construction which is the subject matter of my invention.

Another object of my invention is the provision of a vise-wrench which may be readily and easily l' tion and the accompanying drawing, which is' for the purpose of illustration, and in which: g Fig.- l1 is a vertical elevational viewshowing the manner vin which a vise-wrench constructed in accordance with my present invention is adapted to be held in the hand of a user thereof; @Fig 2 is a vertical, partly elevational, partly sectional view of a wrench constructed in accordance with my invention showing the combined locking and releasing handle in the position which it assumes when the wrench is being released from an object upon which it is clamped; Fig. 3 is a longitudinal, sectional View taken on broken line 3 3 ofV Fig l; and

' Fig. 4 is a cross section taken on line 4 4 of Fig. 1 which shows the manner in which the cam embodied in the locking and releasing handle impinges on the relatively stationary handle of a wrench constructed in accordance with my present invention.

Referring now to the drawing, I show a vise- Wrench it having a relatively stationary handle Il which may be formed from sheet metal or similar material into a channel shape which is inverted to form a downwardly opening, elongated chamber I2. The word stationary is utilized in describing the handle Il in order to convey the idea that the handle l I is not moved to perform the vise-wrench clamping action. It is, of course, not desired to convey the idea that the handle l l is so fixed that it cannot be readily moved and variously positioned by the user of thefwrench. The handle Il is'provided withv a pair of integral, downwardly projecting ears I3 in the forward portion thereof, and a nonmovable jaw member Id having its rear end adjacent the forward edges of said ears is secured in the endof said handle l l by welding or similar means. When the jaw I4 is described as being nonmovable it is intended to convey the idea that the clamping action of the wrench .is-not achieved by'the movement of the nonmovable jaw la in relation to the other elements of the wrench lo.

Pivotally secured to the handleY l Ithrough the medium of a first pivot pin I5 is a jaw mounting plate It w ich is of generally triangular or bellcrank shape and which is housed to a certain extent within the chamber l2 provided by the walls of the channel-shaped handle ll A movable jaw IT is secured to the upper end of the jaw mounting plate I6 through the medium of a rivet I8 or similar fastener and is adapted to be swung upon said jaw mounting plate l5 below the nonmovable jaw I4 in order that it may be adjustedinto a position which will enable it to contact the surface of an object id lpositioned. between it and the'v nonmovable jaw ifi. lWhen my invention 4 the jaw I 'l is described as being movable it is intended to convey not only the idea that the jaw l? is movable with the wrench i@ as a whole, but also the notion that the jaw Il is movable with the jaw mounting plate I S and that the clamping action of the wrench Il is obtained through the movement of the jaw Il in relation to the nonmovaole jaw i4.

The other end of the handle l l of the wrench ill is stamped or otherwise formed into circular shape and has clamped thereupon a circular collar 22 which serves to prevent the spreading of the handle ll and its consequent distortion in lthis region. An internally threaded bore 23 is provided in the circular end of the handle H in which'is threadedly engaged an adjusting bolt orl screw 2lihaving an integral, knurled adjusting knob 25 formed thereupon. That end of the adjusting screw 2d which projects inwardly into the chamber l2 provided by the walls of the handle l is substantially reduced in diameter for a certain portion of its length to provideran adjusting pin 26.

A toggle linkage 2l which consists of a first toggle link 28 and a second toggle link 2e is provided in order that the movement of the adjusting screw 2li maybe communicated to the mounting plate i6 to accomplish the initial adjustment of the movable jaw El in relation to the nonmovable jaw I4, lIhe iirst toggle link 28 has an end thereof projecting into the confines oi the chamber I2 provided by the. walls of the handle Hand has a 'concavity 32 formed therein adapted to register with the adjusting pin 2: and to permit the adjusting pin 26 and the associatedadjusting'screw 24 to drive the end of the iirst toggle link 28 forward within the connues of' the chamber l2 when the adjusting screw 2 is advanced in the bore 23.' The other end of the Erst togglelink 28- extends in the direction of the jaw mounting plate I8. The sec-l ond toggle link 2S is pivota-lly secured to the rear corner of the jaw mounting plate IE through the medium of a second pivot pin 3'3 and has its other end pivotallysecured tothe adjacent end of the rst toggle link 28 through the medium of a third pivot pin 3l.

A downwardly jrojecting, integral tongue 3T is formed in the handle Il and is. adapted to secure one end of a. coil spring 38 which has its other end mounted in a hole 35i provided in thev rear end ofv the jaw mounting plate l5. The coil spring 3s thus connects the handle H with the jaw mounting plate I6 and continuously tends to hold the jaw mounting plate I6 and its associated movable jaw il out of engagement or contiguity to the nonmovable jaw i4.

The second toggle link 29 has a combinedl locking and releasing handle 45 mounted thereupon through ythe medium of the third pivot pin 34. The combined locking and releasing handle d5 may be formed of sheet material into a generally channel-shaped member having the sides 46 thereof enshrouding or covering the greater portion of the second vtoggle link 29. Each of the sides 46 of the combined locking andv releasing handle !l5 has formed therein an elongated, longitudinal slot 4'! which engages the third pivot pin 34 and'permits the combined locking and releasing handle 55 to be moved back va'nd forth over the second toggle link 29. Projecting outwardly from the sides of the second toggle link 29 are detent means which, in the present embodiment of the invention, are constituted by outwardly projecting, integral ears 49 formed inthe body of Vthe second togglev link 29 rearwardly of the second pivot pin 39.

Detent means are provided in the forward edges of the side walls 46 of the combined locking and releasing handle 45. The detent means, in the present embodiment of my invention, consists of notches 5I which are adapted to engage the integral ears 49 formed upon the' second toggle link 29. The second toggle link 29 has a rearwardly extending portion 52 in the end of which is formed a hole 53 adapted to receive the end of a coil spring 54, the other end of which is secured upon an inwardly projecting' integral tongue 55 on the combined locking fand releasing handle 45. The coil spring 54 urges the combined locking and releasing` handle 45 forward over the surface of the second toggle link 29 and causes the detent means 49 of the second toggle link 29 to engage the detent means 5I of the combined lockingl and releasing handle 45, thus causing said second toggle link and said handle to be separably' joined in order that they may cooperate in locking the movable jaw I1 against an object. A nger grip '51 is formed upon the combined locking and releasing handle 45 to facilitate the rearward movement of the combined locking and releasing handle in a manner to be described below. The 'sides 46 of the handle 45 are so extended in the central portion of the handle as tov provide cams 58 which are adapted to contact the'underside of the handle II of the wrench I0.

When an object I9 is to be clamped between the nonmovable jaw I4 and the movable jaw I1 the adjusting screw 24 is advancedplwithin the interior of the handle I I and its movement is transmitted through the toggle linkage 21 to the jaw mounting plate I6 which, ini turn, carries the jaw I1 into contact withthe surface of the object I 9. Since thecoil spring 54 normally retains the detent means 49 and 5I of the combined locking and releasing handle 45 and the second toggle link 29 in registry, the locking of the jawvv I1 against the object vI9 may be A achieved by forcing thecombined locking and releasing handle 45 toward fthe relatively stationary handle II of the wrench II). The movement of the handle 45 and thegsecond toggle link 29 in unison forces the toggle linkage 21 over center upon the third pivot pin 34 and locks the movable jaw I1 in the position into which it was initially adjusted by the adjusting screw 24. When it'is desired to releaseythe object I9 from the nonmovable jaw I4 and the movable ,jaw I1, the combined locking and releasing handle 45 is rst moved backwards` over the second toggle link 29 through the medium of the `linger grip 51 of the handle 45 v,against the force of the coil spring 54. The rearward movement of the handle 45, as best shown in Figs. 1 and 2, disengages the detent means 5I-from the detent -means 49 and permits the union between the `handle 45 and the second togglelink 29 to"be` broken. f

When the detent means 49 is completely disengaged from the detent means 5I, the handle 45 may then be moved inwardly toward the relatively stationary handle II.' .The inward movement 0f the handle 45 causes the cams 58 of the handle 45 to impinge upon the underside of .the handle II and the cams "58fthus provide a fulcrum for the force supplied 'by the hand of the user. As the handle 45 is brought toward the relatively stationary handle II the pivot pin 34 is carried away from the handle lII over the center line of the toggle and the jaw mounting plate I6 and its associated movablejaw I1 are carried away from .the object I9.

'When the user releases his grip the spring 54 moves the handle 45 forward over the second toggle link 29, causing the detent means 49 and 5I vto re-engage and automatically putting the wrench in readiness for'the next gripping operation.

I thus provide by my invention a vise-type wrench which may be readily released from an object upon which it has been clamped and which maybe so released with only one hand. I also provide a vise-type wrench which isv so constructed that a greater mechanical advantage is providedto the user when the wrench is released from an object than when the wrench is initially applied to the object.

Although I have shown and described a preferred embodiment of my device, it will be appreciated that other elements may be substituted for the particular elements shown herein without departing from the spirit of the invention', and I therefore do not intend to be limited to the specific construction shown, and desire to be afforded the full scope of the following claims.

I claim as my invention:

' l. A vise-grip wrench comprising: a rst pivot pin; a handle member on which said first pin is carried, said handle member having a xed jaw on its upper portion above said rst pin and a handle portion extending downwardly below said first pin; an adjusting bolt threaded in the lower end of said handle with its head below the end of said handle, the axis of said bolt pointing in the general direction of said rst pin; a movable jaw member having a movable jaw so placed on its upper portion as to grip an object placed between said jaws; a second pivot pin carried on said movable jaw member, said second pin being positioned to the left of a plane passing through the axis of said rst pin and between the jaws, the axis of said second pin vbeing parallel to the axis of said first pin; a first toggle vlink pivoted at its upper end on said second pin and carrying a third pivot pin, said rst toggle link having an extension Vbelow said third pin; a second toggle link pivoted at its upper end on said third pin, its lower end abutting against the upper end of said adjusting bolt; a locking and releasing handle bent in channel form, the ilanges of said channel extending inwardly from the web of the channel and enclosing the junction of said rst and second toggle links, each of said flanges having a short slot therein, said slots being approximately parallel to the web of the channel and said third pin projecting through and slid-l ing freely in said slots; spring means pulling said locking and releasingv handle upwardly so that the third pin is held normally in the bottom of said slot; mutually engaging means between said rst toggle link above said third pin and. the upper end of said locking and releasing handle so placed that said locking and releasing handle is locked to and can actuate said rst toggle link;'and a projection on said locking and releasing handle which contacts said handle portion of said stationary handle member at a point below saidthird pin when the toggle formed of said rst and second toggle links is near Vits locked position.' if' 4 2. A vise-grip wrench comprising: a first pivot pin; a handle Amember on which said first pin is carried, said handle-member having a fixed idw on its 'upper portion above'said iirst pinfjand a handle portion. extending downwardlybelow said first. pin; an adjusting boltL threaded i'nthe lower end of said handle wit-hits head below the end of said handle, the, axis of said bolt pointing;- in. the; general direction of said first pin; a. movable jaw; member having; a movable jaw so placed on its upper portion as to grip an object placed between said jaws; a second pvot pin carried on. said. movable jaw memben. said second. pin. being positioned to the left. of aplane passing through theA axis of; said first pin. and between the jaws, the axis ofvsaid secondpin being parallel.- to the axis of said` rst pin; a first toggle link. pivoted atv itsl` upper end on. said second pin and: carrying a, third pivot pin; said nlrst toggle link. having an extension. belowsaid third pin; a second toggle link; piyotedl at its upper' end. on said third pin,l itslowerend abutting Aagainst the upper' endof said adjusting bolt; alocking and releasing handle bent in channel form, the nangesf of'.l said' channel. extending inwardly from the web. of the lchannel and enclosing the junction of said first'. and second toggle links, each of said flanges having a short slot Y therein, said slots. being approximately parallel to the web of the; channel and said third pin projecting through and, sliding freely in said slots; spring means pulling; said locking and releasing handle upwardly so that: the third pin is held normally in the. bottom of said slot; a iinger grip projecting trom Said locking and releasing handle near the top thereof to assist anser in pulling the. locking-and releasing handle downwardly againstv the pull' of said spring; mutually engaging means between said first toggle link above said third pin and. the upper end of said locking and releasing handle so placed thaty said locking and releasing handle is locked to and. can actuate said first toggle link; and a projection on said loc-king and rel-easing handle which contacts said handle portion of said stationary handle member at a point below said third pin when the toggle formed of said rst and second toggle links is near its locked position.

3. A vise-gripwrench comprising: a first pivot pin; a handle. member onv which said rst pin is carried, said. handle member having a fixed jaw on its upper portion above said first pin t.

bolt. pointing in the general direction of said l.

rst pin; a movable jawv member having a movable jaw so' placed on its upper portion as to grip an object. placed between said jaws.; spring means acting between said movable jaw member and said handle member to rotate said movable jaw member about said first pin in a counterclockwise direction; a second pivot pin carried on said movable jaw member, said second pin being positioned to the left of a plane passing through the axis of said :firsty pin and between the jaws, the axis of said second pin being parallel to the axis of said first pin;v a first toggle link pivoted at its upper end on said secondpin and carrying a third pivot pin, said first toggle link having an extension below said third pin;

a second toggle link pivoted at its-upper 'end on said third pin, its lower end abutting against theupper end of said adjustingfbolt; a locking and releasing handle bent in channel form, the flanges of said channel extending inwardly Vfrom 8. the-web; ofthe .channel and enclosing thefjunc-l tion of said nrst.' and second toggle links, each ofi said'anges. havingl aA short slot therein, said slots' being approximately parallel to the.y web. 'of the channel' and said third pin projectingl through and sliding freely in said slots; Spring means pulling said locking and releasing handle upwardly so that the third pin is held normally in the. bottom of said slot;V mutually engaging means between said first toggle link above said third pin. and the upper end of said locking and releasing handle soV placed that said locking and releasing handle islocked to.- and canac-tuate said 'rst toggle'link: and a projection on said looking and/'releasing handle which. contactssaidhandle portiony of said' stationary handle member at a point below said-thirdpinl when the toggle formedofsaid rst and second toggle. links is near its-locked position. I v

f li, A vise-grip. wrench comprising: a-first pivot pin; a handle'member on which said-first pin is earriedysaid 'handle member having a fixed jaw on its.: upper portion above said rst pin anda handle portion extending downwardly below said first pin an adjusting bolt threaded in the lower end of'said handle with i-ts head below the end of. said handle, the axis of said bolt pointing in. the general direction of. said first pin; a movable jaw member having a movable jaw so placed on its. upper portion as to grip an object placed between said jaws; spring means acting between said movable jaw member" and said handle member to .rotate said movable jaw memberabout said first pin lin a counterclockwi'se direction.; a se'cornlfpivot pin carried on 'said movable jaw member; said second. pin being positioned tothe left of a plane passing through-the axis of said first pin and between the jaws,A the axis of said second pin being' parallel to the axis of said rSt pin; a first toggle link pivoted at its upper endv on said second pinl and carrying a third pivot pin, said first toggle link having an extension below` said third pin; a second toggle link pivoted at its upper end on said third pin, its lower end abutting against the upper end of said adjusting bolt; a locking and releasing handle bent in channel' foren, the Hanges of said channel extending inwardly from the web of the channel and enclosing vthe junction of said rst and second toggle links, each of said flanges having a short slot therein, s'aid slots being approximately parallel'to the web of the :channel and said third pin projecting through' and sliding freely in said slots; spring means pulling said 'locking and releasing handlev upwardly so that the third pin isvheld normally inthe bottomof said slot; a finger grip projecting from vsaid locking and releasing handle near the top thereof to assist a user'in pulling the locking and releasing handle downwardly against' the pull of said spring; mutually engaging means between said' irst toggle link above saidthirdpin and the upper end of said locking and releasing handle so placed that said locking and releasing handle. is locked to and can actuate said first toggle. link; and a projection on said locking and releasing handle which contacts said handle portion of said stationary handle member at a. point below said third pin when the toggle formed of said first and second toggle links is. near its locked position..

5. A. vise-grip wrench :comprising: a rst-pivot pin; .a ,handle member .on which said .rst pin is carried, said handle member having a xed jaw .on .its upper portion above saidirst pin and a '.-iaridl portieri extending downwardly below said f-rst pin; a thrust member carried on said handle member; a movable jaw member having a movable jaw so placed on its upper portion as to grip an object placed between said jaws; a second pivot pin carried on said movable jaw member, said second pin being positioned to the left of a plane passing through the axis of said rst pin and between the-jaws, the axis of said second pin being parallel to the axis of said rst pin;

nel extending inwardly from the web of the chan- 4 nel and enclosing the junction `of said rst and second toggle links, each of said flanges having a short slot therein, said slots being approximately parallel to the web of the channel and said third pin projecting through and sliding freely in said slots; spring means pulling said locking and releasing handle upwardly so that the third pin is held normally in the bottom of said slot; mutually engaging means between said rst toggle link above said third pin and the upper end of said locking and releasing handle so placed that said locking and releasing handle is locked to and can actuate said first toggle` link; and a projection on said locking and releasing handle which contacts said handle portion of Y said stationary handle member at a point below said third pin when the tog-gle formed of said first and second toggle links is near its locked position.

6. A vise-grip wrench comprising: a first pivot pin; a handle member on which said rst pin is carried, said handle member 'having a xed jaw on its upper portion above said rst pin and a handle portion extending downwardly below said first pin; a thrust member carried on said handle member; a movable jaw member having a movable jaw so placed on its upper portion as to grip an object placed between said jaws; a second pivot pin carried on said movable jaw member, said second pin being positioned to the -left of a plane passing through the axis of said rst pin and between the jaws, the axis of said second pin being parallel to the axis of said first pin; a rst toggle link pivoted at its upper end on said second pin and carrying a third pivot pin, said rst toggle link having an extension below said third pin; a second toggle link pivoted at its upper end on said third pin, its lower end abutting against said thrust member on said handle member; a locking and releasing handle bent in channel form, the ilanges of said channel extending inwardly from the web of the channel and enclosing the junction of said rst and second toggle links, each of said flanges having a short slot therein, said slots being approximately parallel to the web of the channel and said third pin projecting through and sliding freely in said slots; spring means pulling said locking and releasing handle upwardly so that the third pin is held normally in the bottom of said slot; a finger grip projecting from said locking and releasing handle near the top thereof to assist a user Ain pulling the locking and releasing handle downwardly against the pull of said spring; mutually engaging means between said rst toggle link io 1' above said third pin and the upper end of said locking'and releasing'handle so placed that said locking and releasing handle is locked to and can vactuate said rst toggle link; and a projection 'carried' said handleA member having a fixed jaw on its upper portion above said `ilrst pin and a 'handle portion extending downwardly below said `first pin; a thrust member carried on said handle member; 'a movable jaw member having a movable jaw so placed on'its upper portion as to grip an object placed between said jaws spring means lacting between said movable jaw' member and said handle member to rotate said movable jaw member about said rst pin in a counterclockwise direction; a second pivot pin carried on said movable jaw member, said second pin being positioned to the left of a plane passing through the axis of said first pin and between the jaws, the axis of said second pin being parallel to the axis of said rst pin; a rst toggle link pivoted at its upper end on said second pin and carrying a third pivot pin, said first toggle link having an extension below said third pin; a second toggle link pivoted at its upper end on said third pin, its lower end abutting .against said thrust member on` said handle member; a locking and releasing handle bent in channel form, the flanges of said channel extending inwardly from the web of the channel and enclosing the junction of said rst andsecond toggle links, each of said anges having a short slot therein, said slots being aproximately parallel to the web of the channel and said third pin projecting through and sliding freely in said slots; spring means pulling said locking and releasing handle upwardly so that the third pin is held normally in the bottom of said slot; mutually engaging means between said rst toggle link above said third pin and the upper end of said locking and releasing handle so placed that said locking and releasing handle is locked to and can actuate said first toggle link; and a projection on said locking and releasing handle which contacts said handle portion of said stationary handle member at a point below said third pin when the toggle formed of said first and second toggle links is near its locked position. 3. A vise-grip wrench comprising: a first pivot pin; a handle member on which said first pin is carried, said handle member having a xed jaw on its upper portion above said rst pin and a handle portion extending downwardly below said rst pin; a thrust member carried on said handle member; a movable jaw member having a movable jaw so placed on its upper portion as to grip an object placed between said jaws; spring means acting between said movable jaw member and said handle member to rotate said movable jaw member about said first pin in a counterclockwise direction; a second pivot pin carried on said movable jaw member, said second pin being positioned to the left of a plane passing through the axis of said first pin and between the jaws, the axis of said second pin being parallel to the axis of said first' pin; a iirst toggle link pivoted at its upper end on said second pin and carrying a third pivot pin, said rst toggle link having an Vextension below said third pin; a second toggle link pivoted at its upper end on said third pin, its lower end abutting against said thrust memele sgiil hehsile griemhei; e leelsiiig gliel release elle lesi- 1t eheiiiiel iene, the llaiiges @i i;ihel extending ihwaidly .fieri-i the web ei the eliaiirlel and eiielesiiig the junction of seifl ariel .seeegfl teggle links, @geh ef said fl leges Vhaving a sheit slet therein, said .slots @eine appregimately parallel te the gli of lthe and said third pin pieieeting ,thiough and sliding freely said elpts; spring means pulling lsaid locking and releasing handle up- -warilly .se that the third ein is held normally iii ihe betteln el saiel slet; a .iiger grip projecting Afregi sale, leekihg enel releasing handle near the top thereof .te assist user pulling the locking an@ releasing handle downwardly against the pull el said spring; mutually engaging means. between saiel Iirst toggle llnls above said third pin and :the Lipper end ef said leeliing and releasing hanille se pleeed thai said leeking and releasing .handle 4is locke@ te and ,een ,actuaie said first e@ 12 v.tei-aigle lilik; and a projeetion ori vseid locking agid .releasing handle whieh eehtaets said handle portieri of said stetioilary handle member at e peint helew .said third pin when the toggle formed Qi said .rst and .seeeiid teggle links near its .locked position,

BRUCE BURNS- REFERENCES CITED The `following references are of record in the file of this patent:

UNITED STATES PATENTS 

